Metal pillar in a film-type seconductor package

ABSTRACT

A film-type semiconductor package includes a metal lead portion arranged on a film substrate, a semiconductor chip including a pad, and a bump connecting the metal lead portion to the pad of the semiconductor chip. The bump includes a metal pillar arranged on the pad and including a first metal and a soldering portion arranged on an entire surface of the metal pillar, bonded to the metal lead portion, and including the first metal and a second metal that is different from the first metal.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No. 15/456,882, filed Mar. 13, 2017, which claims the benefit of priority from Korean Patent Application No. 10-2016-0125590, filed on Sep. 29, 2016, in the Korean Intellectual Property Office, the entire contents of each of which are incorporated herein by reference.

BACKGROUND

The inventive concepts relate to a film-type semiconductor package and a manufacturing method thereof, and/or to a film-type semiconductor package using a film substrate and a manufacturing method thereof.

A film-type semiconductor package, e.g., a chip on film (COF) semiconductor package, is typically manufactured by bonding a bump arranged on a pad of a semiconductor chip and a metal lead portion arranged on a film substrate.

Along with the trend toward miniaturization, slimness, lighter weight, and high performance of electronic devices, the bump typically present in a film-type semiconductor package has become increasingly finer. Accordingly, a reliable bonding process may be advantageous when applied between the bump and the metal lead portion when the film-type semiconductor package is manufactured. In addition, when the bump and the metal lead portion are bonded to each other, bending of the film substrate while the bump is bonded to the metal lead portion may be reduced.

SUMMARY

The inventive concepts relate to a film-type semiconductor package capable of reducing bending of a film substrate and more reliably bonding a bump and a metal lead portion to each other.

The inventive concepts relate to a method of manufacturing the film-type semiconductor package.

According to an example embodiment of the inventive concepts, a film-type semiconductor package includes a metal lead portion arranged on a film substrate, a semiconductor chip including a pad, and a bump connecting the metal lead portion and the pad of the semiconductor chip. The bump may include a metal pillar on the pad and a first metal, and a soldering portion on an entire surface of the metal pillar, bonded to the metal lead portion, and including the first metal and a second metal different from the first metal.

According to another example embodiment of the inventive concepts, a film-type semiconductor package includes a metal lead portion extending from an outer lead bonding portion at one side portion of a film substrate to an inner lead bonding portion, a semiconductor chip including a pad, and a bump connecting the metal lead portion of the inner lead bonding portion and the pad of the semiconductor chip. The bump may include a metal pillar on the pad and a first metal, and a soldering portion on an entire surface of the metal pillar, bonded to the metal lead portion, and may include the first metal and a second metal different from the first metal.

According to another example embodiment of the inventive concepts, a film-type semiconductor package includes a metal lead portion on a film substrate and including a copper layer, a semiconductor chip including a pad, and a bump connecting the metal lead portion and the pad of the semiconductor chip. The bump may include a metal pillar on the pad and a gold layer or a copper layer, and a soldering portion on an entire surface of the metal pillar, may include a gold-tin eutectic alloy layer, and may be bonded to the metal lead portion.

According to another example embodiment of the inventive concepts, a method of manufacturing a film-type semiconductor package includes forming a film substrate including a metal lead portion, forming a metal pillar on a pad of a semiconductor chip, forming a first solder layer on the metal pillar, forming a second solder layer on the first solder layer to form a preliminary bump including the metal pillar, the first solder layer, and the second solder layer, and thermally compressing the metal lead portion and the first and second solder layers of the preliminary bump to form a bump including a soldering portion that bonds the metal lead portion to the pad of the semiconductor chip.

Some example embodiments relate to a bonding bump bonded to a lead portion in a semiconductor package, the bonding bump including a metal pillar including a first metal, and a soldering portion including a first soldering layer on the metal pillar, the soldering portion being bonded to the metal lead portion and including a eutectic alloy layer of the first metal.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments of the inventive concepts will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a block diagram illustrating a display device employing a film-type semiconductor package according to an example embodiment;

FIG. 2 is a plan view schematically illustrating a film-type semiconductor package according to an example embodiment;

FIG. 3 is a cross-sectional view illustrating a connection between a semiconductor chip and a film substrate of the film-type semiconductor package of FIG. 2;

FIG. 4 is a cross-sectional view illustrating a film-type semiconductor package according to an example embodiment;

FIG. 5 is a cross-sectional view illustrating a structure of a bump of a film-type semiconductor package according to an example embodiment;

FIG. 6 is a cross-sectional view illustrating a structure of a bump of a film-type semiconductor package according to an example embodiment;

FIG. 7 is a flowchart illustrating a method of manufacturing a film-type semiconductor package according to an example embodiment;

FIGS. 8 to 12 are cross-sectional views illustrating a method of manufacturing a film-type semiconductor package according to an example embodiment;

FIGS. 13 and 14 are cross-sectional views illustrating a configuration of a preliminary bump prepared for manufacturing a film-type semiconductor package according to an example embodiment;

FIG. 15 is a phase diagram of elements constituting a solder layer of a film-type semiconductor package according to an example embodiment; and

FIG. 16 is a block diagram illustrating a configuration of a display device including a film-type semiconductor package according to an example embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, example embodiments will be explained in detail with reference to the accompanying drawings.

When the terms “about” or “substantially” are used in this specification in connection with a numerical value, it is intended that the associated numerical value include a tolerance of ±10% around the stated numerical value. Moreover, when reference is made to percentages in this specification, it is intended that those percentages are based on weight, e.g., weight percentages. The expression “up to” includes amounts of zero to the expressed upper limit and all values therebetween. When ranges are specified, the range includes all values therebetween such as increments of 0.1%. Moreover, when the words “generally” and “substantially” are used in connection with geometric shapes, it is intended that precision of the geometric shape is not required but that latitude for the shape is within the scope of the disclosure. Although the tubular elements of the embodiments may be cylindrical, other tubular cross-sectional forms are contemplated, such as square, rectangular, oval, triangular and others.

A film-type semiconductor package, e.g., a chip-on-film semiconductor package, may be applied to a mobile terminal device, a laptop computer, or a display device, e.g., a flat panel display device. Since the display device is driven by a semiconductor chip including input/output terminals configured to perform various functions and has become thinner, the film-type semiconductor package may be applied to the display device.

Hereinafter, for the convenience of explanation, the film-type semiconductor package applied to the semiconductor chip, e.g., a display drive IC (integrated circuit) included in the display device, will be described as a representative example. The display drive IC may be referred to as a “display driver IC”.

FIG. 1 is a block diagram illustrating a display device 500 employing a film-type semiconductor package according to an example embodiment.

In detail, the display device 500 may include the film-type semiconductor package 100, a source drive printed circuit board (PCB) 300, a gate drive PCB 400, and an image display panel 550.

The source drive PCB 300 and the gate drive PCB 400 may provide a signal to the image display panel 550 to allow an image to be displayed through each, or at least one, pixel of the image display panel 550. The image display panel 550 may display the image on the basis of the signal applied thereto.

The chip-on-film semiconductor package may be used as the film-type semiconductor package 100. The film-type semiconductor package 100 may receive the signal output from the source driver PCB 300 and the gate driver PCB 400 and transmit the received signal to the image display panel 550.

FIG. 2 is a plan view schematically illustrating a film-type semiconductor package according to an example embodiment, and FIG. 3 is a cross-sectional view illustrating a connection between a semiconductor chip and a film substrate of the film-type semiconductor package of FIG. 2.

In detail, the film-type semiconductor package 100 may include a film substrate 110, a metal lead portion 130, a semiconductor chip 210, and a bump 230. An output pin OPIN is arranged at one end portion of the film substrate 110, and an input pin IPIN is arranged at the other end portion of the film substrate 110.

The film substrate 110 may be, but not limited to, a polyimide substrate. The metal lead portion 130 may include a copper layer. As described later, the metal lead portion 130 may include a metal lead, e.g., a copper layer, and a lead protective layer, e.g., a tin layer, protecting the copper layer. The film substrate 110 and the metal lead portion 130 may be referred to as a “film member”. The film substrate 110 and the metal lead portion 130 may be referred to as a “tape carrier”.

The film-type semiconductor package 100 may include the semiconductor chip 210 provided with a pad 220 arranged in one surface of the semiconductor chip 210, and the bump 230 arranged on the pad 220 of the semiconductor chip 210. The semiconductor chip 210 may be mounted on the film substrate 110. The semiconductor chip 210 may be provided in a package form, and thus the semiconductor chip 210 may be a semiconductor package.

The pad 220 may include, for example, a copper layer or an aluminum layer but is not limited thereto. The pad 220 of the semiconductor chip 210 may be an edge pad arranged at a circumferential portion of a chip body 210 s. The pad 220, if necessary, may be a center pad arranged at a center portion of the chip body 210 s. The number or arrangement of the pads 220 may be implemented in a variety of ways according to a design applied to the film-type semiconductor package 100. The pad 220 may include a power pad, a ground pad, and a signal input/output pad.

The film-type semiconductor package 100 may be formed by bonding the bump 230 arranged on the one surface of the semiconductor chip 210 to the metal lead portion 130 arranged on the film substrate 110. The bump 230 and the metal lead portion 130 may be bonded to each other by a thermal compression process as described below.

The bump 230 may be arranged on an active surface of the semiconductor chip 210, e.g., on a surface on which a circuit is formed. The bump 230 may protrude from the active surface of the semiconductor chip. The bump 230 may be arranged on a lower surface of the chip body 210 s. The bump 230 may be arranged at a circumferential portion of the semiconductor chip 210. The bump 230 may be arranged at a center portion of the semiconductor chip 210 according to a position of the pad 220.

The semiconductor chip 210 and the metal lead portion 130 may be electrically connected to each other through the bump 230 that is located on the one surface of the semiconductor chip 210 of the film-type semiconductor package 100.

The metal lead portion 130 may be electrically connected to the input and output pins IPIN and OPIN on the film substrate 110. The pad 220 of the semiconductor chip 210 may be connected to the metal lead portion 130 that is located on the film substrate 110 through the bump 230. The metal lead portion 130 may be arranged on the film substrate 110 in a variety of ways according to a design applied to the film-type semiconductor package 100. The pad 220 may be electrically connected to the input and output pins IPIN and OPIN through the bump 230 and the metal lead portion 130.

The metal lead portion 130 may include an outer lead bonding portion OLB and an inner lead bonding portion ILB. The metal lead portion 130 may extend to the inner lead bonding portion ILB from the outer lead bonding portion OLB at one side portion of the film substrate 110.

The inner lead bonding portion ILB may be a portion at which the semiconductor chip 210 is bonded to the film substrate 110. The outer lead bonding portion OLB may be a portion at which the image display panel 550 (refer to FIG. 1) is bonded to the source and gate drive PCBs 300 and 400 (refer to FIG. 1).

Along with the trend toward miniaturization, slimness, lighter weight, and high performance of electronic devices, the number of pads 220 and bumps 230 can be increased. The film-type semiconductor package 100 may advantageously have high reliability of the bonding between the bump 230 that is located on the one surface of the semiconductor chip 210 and the metal lead portion 130 that is located on the film substrate 110. In addition, it may be advantageous that the bonding process of the bump 230 and the metal lead portion 130 in the film-type semiconductor package 100 is easily performed, and that the film substrate 110 is not bent.

Accordingly, the film-type semiconductor package 100 may include the bump 230 having a soldering portion 230 f so as to improve the bonding reliability and hinder or prevent the film substrate 110 from being bent. The structure and material of the bump 230 will be described in more detail below.

FIG. 4 is a cross-sectional view illustrating a film-type semiconductor package 100-1 according to an example embodiment.

In FIG. 4, the same reference numerals denote the same elements in FIGS. 1 to 3. The film-type semiconductor package 100-1 may correspond to the film-type semiconductor package 100 of FIGS. 1 to 3. The film-type semiconductor package 100-1 may further include an electronic element 232, a support plate 234, connectors 236 and 238, and an underfill layer 240.

The film-type semiconductor package 100-1 may include a metal lead portion 130 arranged on a film substrate 110 and a resist layer 132 arranged on the metal lead portion 130 so as to expose a portion of the metal lead portion 130. Although in FIG. 4, the resist layer 132 is arranged only above an upper surface of the film substrate 110, an additional resist layer may be arranged on a lower surface of the film substrate 110. The semiconductor chip 210 and the electronic element 232 may be mounted on the metal lead portion 130.

The semiconductor chip 210 may be bonded to the metal lead portion 130 through the bump 230 including the soldering portion 230 f. The semiconductor chip 210 may protect the bump 230 with the underfill layer 240 arranged on the film substrate 110. The electronic element 232 may be bonded to the metal lead portion 130 by an adhesive layer 242. The electronic element 232 may be configured to perform various functions as a surface mount device. The electronic element 232 may include, for example, an active element, a passive element, and a semiconductor chip.

In the film-type semiconductor package 100-1, the connectors 236 and 238 may be respectively arranged at the metal lead portions 130 in opposite end portions, e.g., one end portion and the other end portion, of the film substrate 110 as an outer lead bonding portion OLB. The connectors 236 and 238 may be bonded to the image display panel 550 (refer to FIG. 1) and the source and gate drive PCBs 300 and 400 (refer to FIG. 1). In some example embodiments, the support plate 234 may be arranged on a lower surface of the film substrate 110 to support the film substrate 110 in the film-type semiconductor package 100-1.

FIG. 5 is a cross-sectional view illustrating a structure of a bump of a film-type semiconductor package according to an example embodiment.

In detail, FIG. 5 illustrates a bump structure in the film-type semiconductor packages 100 and 100-1 of FIGS. 1 to 4 and a connection relation 100 a between the film substrate 110 and the pad 220 of the semiconductor chip 210 using the bump 230. In FIG. 5, the same reference numerals denote the same elements illustrated in FIGS. 1 to 4.

The metal lead portion 130 arranged on the film substrate 110 may be connected to the pad 220 of the semiconductor chip 210 via the bump 230. The film-type semiconductor packages 100 and 100-1 illustrated in FIGS. 1 to 4 may be manufactured by bonding the bump 230 arranged on the one surface of the semiconductor chip 210 to the metal leading portion 130 on the film substrate 110.

The bump 230 and the metal lead portion 130 may be bonded to each other by a thermal compression process as described below. In FIG. 5, the film substrate 110 is at a relatively upper position with respect to the bump 230 and/or the metal lead portion 130, and the semiconductor chip 210 is at a relatively lower position with respect to the bump 230 and/or the metal lead portion 130. Accordingly, the metal lead portion 130 and the bump 230 may be bonded to each other by applying pressure and heat to the film substrate 110 using a pressurizing and heating unit.

The metal lead portion 130 may include a metal lead 130 a and a lead protective layer 130 b protecting a surface of the metal lead 130 a. The metal lead 130 a may include a copper layer, and the lead protective layer 130 b may include a tin layer.

The pad 220 that is protected by a pad protective layer 224 may be disposed on the surface of the semiconductor chip 210. The pad 220 may include the copper layer and the aluminum layer. The pad protective layer 224 may include an insulating layer, e.g., a silicon nitride layer. The bump 230 may be disposed on the pad 220 to be connected to the metal lead portion 130.

The bump 230 may be arranged above the pad 220 and may include a metal pillar 230 a including a first metal, e.g., gold or copper. The bump 230 may include the soldering portion 230 f arranged over an entire surface of the metal pillar 230 a, bonded to the metal lead portion 130, and containing a second metal, e.g., tin, which may be different from the first metal. In other words, the bump 230 may include the metal pillar 230 a arranged above the pad 220 and the soldering portion 230 f arranged over the entire surface of the metal pillar 230 a and bonded to the metal lead portion 130.

The metal pillar 230 a may include a first gold layer and a copper layer. The metal pillar 230 a may include a gold layer having low reactivity or low mutual atomic diffusivity with respect to the soldering portion 230 f. The bump 230, if necessary, may further include a barrier layer 230 r arranged on the pad 220. The barrier layer 230 r may facilitate forming the metal pillar 230 a on the pad 220. The barrier layer 230 r may include a metal layer, e.g., a titanium layer, a titanium nitride layer, etc.

The soldering portion 230 f may include a gold-tin eutectic alloy layer including the first metal and the second metal as described above. As described below, the soldering portion 230 f may include the gold-tin eutectic alloy layer obtained by alloying a second solder layer, e.g., a gold layer, and a first solder layer, e.g., a tin layer having a melting point that is lower than the melting point of the gold layer. The gold-tin eutectic alloy layer contains tin atoms of about 25 at % to about 45 at %. The soldering portion 230 f may surround a bottom surface and opposite side surfaces of the metal lead portion 130.

The bump 230 may further include the second soldering layer, e.g., the gold layer, and the first solder layer, e.g., the tin layer having a lower melting point than the melting point of the second solder layer in addition to the soldering portion 230 f in order to lower compression pressure and a compression temperature of the pressurizing and heating unit during the thermal compression process connecting the metal lead portion 130 to the bump 230 (or a preliminary bump 230 p of FIG. 12).

Accordingly, the metal lead portion 130 and the pad 220 of the film-type semiconductor packages 100 and 100-1 may be reliably connected to each other through the bump 230. In addition, the film-type semiconductor packages 100 and 100-1 may lower the compression pressure and the compression temperature of the pressurizing and heating unit during the thermal compression process connecting the metal lead portion 130 to the bump 230, and thus bending of the film substrate 110 may be reduced or prevented.

FIG. 6 is a cross-sectional view illustrating a structure of a bump of a film-type semiconductor package according to an example embodiment.

In detail, FIG. 6 illustrates a bump structure in the film-type semiconductor packages 100 and 100-1 of FIGS. 1 to 4 and a connection relation 100 b between the film substrate 110 and the pad 220 of the semiconductor chip 210 using a bump 230-1. In FIG. 6, the same reference numerals denote the same elements in FIGS. 1 to 5.

The connection relation 100 b between the film substrate 110 and the pad 220 of the semiconductor chip 210 of FIG. 6 may have the same structure as the structure of the connection relation 100 a of FIG. 5 except that the bump 230-1 further includes a diffusion preventing layer 230 s. Detailed descriptions of the same elements will be omitted in order to avoid redundancy.

The bump 230-1 may connect the metal lead portion 130 arranged on the film substrate 110 to the pad 220 of the semiconductor chip 210. The bump 230-1 may include a metal pillar 230 a arranged on the pad 220 and including a first metal, e.g., gold or copper, the diffusion preventing layer 230 s arranged on the metal pillar 230 a and including a third metal, e.g., nickel, and a soldering portion 230 f arranged over an entire surface of the diffusion preventing layer 230 s, bonded to the metal lead portion 130, and including the first metal and a second metal that is different from the first or third metal, e.g., tin.

The metal pillar 230 a may include a gold layer or a copper layer. The diffusion preventing layer 230 s may include a metal layer having a higher melting point than a melting point of tin in the soldering portion 230 f. The diffusion preventing layer 230 s may include a nickel layer.

The diffusion preventing layer 230 s may hinder or prevent elements constituting the metal pillar 230 a, such as copper, from exerting an influence on the soldering portion 230 f after being diffused. When the diffusion preventing layer 230 s is formed as illustrated in FIG. 6, the metal pillar 230 a may include a copper layer because the reactivity or the mutual atomic diffusivity of the metal pillar 230 a with respect to the soldering portion 230 f may not be considered.

FIG. 7 is a flowchart illustrating a method of manufacturing a film-type semiconductor package according to an example embodiment, and FIGS. 8 to 12 are cross-sectional views illustrating a method of manufacturing a film-type semiconductor package according to an example embodiment.

In detail, as illustrated in FIGS. 7 and 8, the manufacturing method of the film-type semiconductor package includes forming the film substrate 110 including the metal lead portion 130 (S310). The metal lead portion 130 is formed on a surface of the film substrate 110. As described above, the metal lead portion 130 includes the metal lead 130 a, e.g., the copper layer, and the lead protective layer 130 b, e.g., the tin layer.

As illustrated in FIGS. 7 and 9, the barrier layer 230 r and the metal pillar 230 a are formed on the pad 220 of the semiconductor chip 210 (S320). The pad 220 may be restricted by the pad protective layer 224. The barrier layer 230 r may also be formed, if necessary.

The barrier layer 230 r may include a metal layer, e.g., the titanium layer or the titanium nitride layer as described above. The metal pillar 230 a may include a gold layer or a copper layer. The barrier layer 230 r and the metal pillar 230 a may be aligned with the pad 220. In other words, the barrier layer 230 r and the metal pillar 230 a may be formed on the pad 220 restricted by a mask layer 226 formed on the semiconductor chip 210.

As illustrated in FIGS. 7, 10, and 11, the diffusion preventing layer 230 s is formed on the metal pillar 230 a (S330). As described above, the diffusion preventing layer 230 s may be formed as needed. For example, the diffusion preventing layer 230 s may include a nickel layer.

A solder layer 230 e may be formed, for example subsequently formed, on the diffusion preventing layer 230 s (S340). The solder layer 230 e may include the first solder layer 230 b formed on the diffusion preventing layer 230 s and the second solder layer 230 c formed on the first solder layer 230 b.

The first solder layer 230 b may include a metal layer having a melting point lower than the melting point of the second solder layer 230 c. The first solder layer 230 b may include a tin layer. The second solder layer 230 c may include a gold layer. The preliminary bump 230 p configured to include the barrier layer 230 r, the metal pillar 230 a, the first solder layer 230 b, and the second solder layer 230 c may be formed on the pad 220 by the above-mentioned processes, as illustrated in FIG. 10.

The barrier layer 230 r, the metal pillar 230 a, the first solder layer 230 b, and the second solder layer 230 c, which are described above, may be formed by various methods, such as, for example, a thermal deposition method, an electron-beam deposition method, a sputter method, an electroplating method, an electroless plating method, etc.

When the mask layer 226 (refer to FIG. 10) is removed, the preliminary bump 230 p may be completed as illustrated in FIG. 11. The preliminary bump 230 p may be provided in a state where the preliminary bump 230 p is electrically connected to the pad 220 of the semiconductor chip 210.

Referring to FIGS. 5, 6, 7, and 12, the metal lead portion 130 and the preliminary bump 230 p may be thermally compressed to form a eutectic alloy layer, thereby forming the bumps 230 and 230-1 (refer to FIGS. 5 and 6) having the soldering portion 230 f (refer to FIGS. 5 and 6) (S350). FIG. 12 illustrates a state where the film substrate 110 including the metal lead portion 130 is separated from the semiconductor chip 210 on which the preliminary bump 230 p is formed.

The preliminary bump 230 p may be used to describe the state in which the semiconductor chip 210 is not bonded to the metal lead portion 130, and the preliminary bump 230 p may be a bump as a general concept. The preliminary bump 230 p may be formed to have a three-layer structure including the metal pillar 230 a, the first solder layer 230 b, and the second solder layer 230 c. The preliminary bump 230 p may be formed to have a four-layer structure of the metal pillar 230 a, the diffusion preventing layer 230 s, the first solder layer 230 b, and the second solder layer 230 c.

The thermal compression process for the metal lead portion 130 and the preliminary bump 230 p may be a process of bonding the metal lead portion 130 to the preliminary bump 230 p by applying pressure and heat to the film substrate 110 and to the preliminary bump 230 p via the pressurizing and heating unit. The soldering portion 230 f (refer to FIGS. 5 and 6) may be formed by melting the first solder layer 230 b and the second solder layer 230 c, which results in the forming of the eutectic alloy layer.

Due to the thermal compression process for the metal lead portion 130 and the preliminary bump 230 p, the eutectic alloy layer is formed after the metal lead portion 130 and the preliminary bump 230 p make contact with each other via the pressurizing and heating unit, as illustrated by the arrows of FIG. 12.

For instance, the bonding process may be performed by applying a pressure of about 10 kgf/cm² to about 20 kgf/cm² to the film substrate 110 and the preliminary bump 230 p at a temperature of about 300° C. to about 400° C. for a period of time of several seconds to several tens of seconds. However, the above-mentioned example bonding process conditions may be changed, and other bonding conditions may be used that result in having the metal lead portion 130 and the preliminary bump 230 p bonded to each other by forming a eutectic alloy layer.

To more easily form the eutectic alloy layer, the soldering portion 230 f (refer to FIGS. 5 and 6) may include a gold-tin eutectic alloy layer obtained by alloying the second solder layer 230 c, e.g., the gold layer, and the first solder layer 230 b, e.g., the tin layer having a melting point lower than the melting point of the gold layer. The gold-tin eutectic alloy layer contains tin atoms of about 25 at % to about 45 at %.

FIGS. 13 and 14 are cross-sectional views illustrating a configuration of a preliminary bump prepared for manufacturing a film-type semiconductor package according to an example embodiment.

In some example embodiments, as described above, a preliminary bump 230 p-1 or a preliminary bump 230 p-2 may be formed on the pad 220 when the film-type semiconductor package is manufactured, the preliminary bump 230 p-1 including a barrier layer 230 r, a metal pillar 230 a, a first solder layer 230 b, and a second solder layer 230 c-1, and the preliminary bump 230 p-2 including a barrier layer 230 r, a metal pillar 230 a, a first solder layer 230 b, and a second solder layer 230 c-2. The second solder layer 230 c-1 of the preliminary bump 230 p-1 illustrated in FIG. 13 may have a thickness T3 that is different from a thickness T4 of the second solder layer 230 c-2 of the preliminary bump 230 p-2 illustrated in FIG. 14.

The metal pillar 230 a may have a thickness T1 of about several tens of micrometers (μm). The first solder layer 230 b may have a thickness T2 of about several micrometers (μm). The thickness T2 of the first solder layer 230 b illustrated in FIG. 13 may be greater than the thickness T3 of the second solder layer 230 c-1.

The thickness T3 of the second solder layer 230 c-1 illustrated in FIG. 13 may correspond to about 50% of the thickness T2 of the first solder layer 230 b. A thickness T2 of the first solder layer 230 b illustrated in FIG. 14 may be greater than the thickness T4 of the second solder layer 230 c-2. The thickness T4 of the second solder layer 230 c-2 illustrated in FIG. 14 may correspond to about 10% to about 30% of the thickness T2 of the first solder layer 230 b.

In FIGS. 13 and 14, when the metal lead portion 130 and the preliminary bumps 230 p-1 and 230 p-2 are thermally compressed, solder atoms, e.g., the tin atoms, in the first solder layer 230 b in the preliminary bumps 230 p-1 and 230 p-2 may form a solid solution in the metal pillar 230 a and the second solder layers 230 c-1 and 230 c-2, as illustrated by the arrows in FIGS. 13 and 14, and thus the soldering portion 230 f (refer to FIG. 5) may be formed.

As described above, the metal pillar 230 a may be thicker than the first solder layer 230 b. The thickness T2 of the first solder layer 230 b may be greater than the thickness T3 of the second solder layer 230 c-1 and the thickness T4 of the second solder layer 230 c-2. In this case, the soldering portion 230 f (refer to FIG. 5) may be formed by the thermal compression process of the metal lead portion 130 and the preliminary bumps 230 p-1 and 230 p-2.

FIG. 15 is a phase diagram of elements constituting a solder layer of a film-type semiconductor package according to an example embodiment.

In detail, FIG. 15 illustrates the phase diagram of the solder layer of the example film-type semiconductor package described above, e.g., the gold-tin eutectic alloy layer. As described with reference to FIG. 12, the soldering portion 230 f (refer to FIGS. 5 and 6) may be formed via the thermal compression process performed on the metal lead portion 130 and the preliminary bump 230 p.

The preliminary bump 230 p (refer to FIG. 12) may include the first solder layer 230 b (refer to FIG. 12), e.g., the tin layer, and the second solder layer 230 c (refer to FIG. 12), e.g., the gold layer. The soldering portion 230 f (refer to FIGS. 5 and 6) may include a gold-tin eutectic alloy layer through a eutectic reaction of the first solder layer 203 b and the second solder layer 230 c.

As illustrated in FIG. 15, a point at which the eutectic reaction occurs when a temperature is about 280° C. and the tin atoms in the gold-tin alloy is about 29.0 at %, may be called a eutectic point. When the temperature is equal to or less than about 280° C. and the content of tin atoms in the gold-tin alloy is equal to or greater than about 17 at % and equal to or less than about 50 at %, the gold-tin alloy may be present in a zeta phase. When the temperature is equal to or less than about 280° C. and the content of tin atoms in the gold-tin alloy is equal to or greater than about 50 at %, the gold-tin alloy may be present in a delta phase.

On the basis of the above, when the thermal compression process is performed on the metal lead portion 130 and the preliminary bump 230 p, the content of tin atoms in the gold-tin solder layer may be maintained between about 25 at % and about 45 at %, and the compression (bonding) temperature may be maintained between about 300° C. and about 400° C. In addition, the compression pressure (bonding pressure) may be maintained between about 10 kgf/cm² and about 20 kgf/cm², and the compression (bonding) process is performed during several seconds to several tens of seconds. The gold-tin solder layer forms a solid solution by the compression (bonding) process, and thus the gold-tin eutectic alloy layer may be formed.

According to the film-type semiconductor package, the compression (bonding) temperature and the pressure may be lowered by the above-mentioned compression (bonding) process when the preliminary bump 230 p including the metal pillar 230 a and the solder layers 230 b and 230 c are thermally compressed. In addition, bending of the film substrate 110 (refer to FIG. 12) of the film-type semiconductor package may be reduced or prevented, and the gold-tin eutectic alloy layer may be easily formed.

FIG. 16 is a block diagram illustrating a configuration of a display device including a film-type semiconductor package according to an example embodiment.

Referring to FIG. 16, a flat panel display device 500 may include the image display panel 550 and the source drive PCB 300 applying a driving signal to the image display panel 550 through the film-type semiconductor package 100. The image display panel 550 may include, for example, a liquid crystal display panel.

Although not illustrated in the figures, the source drive PCB 300 may include a power unit, a memory unit, a program unit, and a buffer unit, which are built therein. The power provided to the power unit of the source drive PCB 300 from an external power supply source is applied to circuits, such as the memory unit, the program unit, and the buffer unit of the source drive PCB 300. The power unit of the source drive PCB 300 applies a power source voltage to the image display panel 550 through a power line 172 of the film-type semiconductor package 100 to display an image.

The semiconductor chip 210, such as a source drive IC, is mounted on the film-type semiconductor package 100 to apply the driving signal to the image display panel 550 from the source drive PCB 300. As described above, the power source voltage and operation signals for display of the image display panel 550 are transmitted to the image display panel 550 through the film substrate 110 (refer to FIG. 2) and the semiconductor chip 210, such as the source drive IC, mounted on the film substrate 110.

A signal line 152 is connected between the source drive PCB 300 and the semiconductor chip 210 on the film-type semiconductor package 100. The signal line 152 may constitute an input circuit. A signal line 154 is formed between the semiconductor chip 210 and the image display panel 550 on the film-type semiconductor package 100. The signal line 154 may constitute an output circuit.

The power line 172 and a ground line 174 are connected between the source drive PCB 300 and the semiconductor chip 210 on the film-type semiconductor package 100. A power line 162 and a ground line 164 are formed between the semiconductor chip 210 and the image display panel 550 on the film-type semiconductor package 100. The power lines 162 and 172 and the ground lines 164 and 174 are prepared to apply power to the image display panel 550.

While the inventive concepts have been described in connection with the example embodiments, it is to be understood by those who skilled in the art that the inventive concepts are not limited to the disclosed example embodiments, but, on the contrary, are intended to cover various modifications, substitutions, and equivalent arrangements included within the spirit and scope of the appended claims. The example embodiments may be constructed and/or utilized independently or in combination with any other example embodiment contained herein.

Therefore, the disclosed subject matter should not be limited to any single example embodiment described herein, and the above-described example embodiments are to be considered illustrative and not restrictive. Accordingly, the scope of the inventive concepts shall be determined only according to the attached claims. 

What is claimed is:
 1. A film-type semiconductor package comprising: a semiconductor chip; a pad positioned on the semiconductor chip; a pad protective layer positioned around the pad to protect the pad; a barrier layer positioned on the pad; a metal pillar positioned on the barrier layer; a first solder layer positioned on the metal pillar; and a second solder layer positioned directly on the first solder layer, the first solder layer and the second solder layer combine in a soldering portion, the first solder layer having a lower melting point than the second solder layer.
 2. The film-type semiconductor package of claim 1, further comprising; a film member having a metal lead portion positioned to face the second solder layer.
 3. The film-type semiconductor package of claim 2, wherein the metal lead portion is embedded in the solder portion.
 4. The film-type semiconductor package of claim 1, wherein the pad protective layer is formed on the semiconductor chip on an upper surface and a side surface of the pad.
 5. The film-type semiconductor package of claim 1, wherein the barrier layer is formed on a side surface and an upper surface of the pad protective layer.
 6. The film-type semiconductor package of claim 1, wherein the metal pillar is formed on an entire surface of the barrier layer, and the metal pillar comprises a gold layer or a copper layer.
 7. The film-type semiconductor package of claim 1, wherein the first solder layer is formed on an entire surface of the metal pillar, and the second solder layer is formed on an entire surface of the first solder layer.
 8. The film-type semiconductor package of claim 1, wherein the second solder layer has a smaller thickness than the first solder layer.
 9. The film-type semiconductor package of claim 1, wherein the first solder layer comprises a tin layer and the second solder layer comprises a gold layer.
 10. A film-type semiconductor package comprising: a semiconductor chip; a pad positioned on the semiconductor chip; an insulating layer having an opening for opening an upper portion of the pad; a barrier layer positioned on the insulating layer and the opening on the pad and having a step; a metal pillar positioned on the barrier layer; a diffusion prevention layer positioned on the metal pillar; a first solder layer positioned on the diffusion prevention layer; and a second solder layer positioned directly on the first solder layer, the first solder layer and the second solder layer combine in a soldering portion, the first solder layer having a lower melting point than the second solder layer.
 11. The film-type semiconductor package of claim 10, wherein the insulating layer is formed on a part of an upper surface of the pad and a side surface of the pad, and the opening opens a part of an upper portion of the pad.
 12. The film-type semiconductor package of claim 10, wherein the insulating layer is formed on a part of an upper surface of the pad, and the barrier layer is formed on the insulating layer formed on the part of the upper surface of the pad.
 13. The film-type semiconductor package of claim 10, wherein the metal pillar is formed on an entire surface of the barrier layer having the step.
 14. The film-type semiconductor package of claim 10, wherein the diffusion prevention layer is formed on an entire surface of the metal pillar.
 15. The film-type semiconductor package of claim 10, wherein the metal pillar comprises a copper layer or a gold layer, the first solder layer comprises a tin layer, and the diffusion prevention layer comprises a nickel layer.
 16. A film-type semiconductor package comprising: a semiconductor chip; a pad positioned on the semiconductor chip; an insulating layer positioned around the pad; a barrier layer positioned on the pad; a metal pillar positioned on the barrier layer; a diffusion prevention layer positioned on the metal pillar; a soldering portion formed on the diffusion prevention layer, wherein one side surface of the barrier layer, one surface of the soldering portion, and one side surface of the metal pillar are located on a same plane, the soldering portion includes a combined first solder layer and second solder layer, the first solder layer on the diffusion prevention layer, the second solder layer directly on the first solder layer; and a film member having a metal lead positioned on the soldering portion and a lead protective layer surrounding a side surface of the metal lead.
 17. The film-type semiconductor package of claim 16, wherein the soldering portion is located on an entire surface of the diffusion prevention layer.
 18. The film-type semiconductor package of claim 16, wherein one side surface of the diffusion prevention layer and one side surface of the soldering portion are located on a same plane.
 19. The film-type semiconductor package of claim 16, wherein the soldering portion surrounds a bottom and both side surfaces of the metal lead.
 20. The film-type semiconductor package of claim 16, wherein the metal lead comprises a copper layer and the lead protective layer comprises a tin layer. 